The Sept. 19 release date is likely an educated guess as it is consistent with the company’s recent iPhone launches.
Apple

Apple’s (NASDAQ:AAPL) upcoming flagship smartphone iteration, unofficially dubbed the “iPhone 6,” is highly expected to be faster and lighter than its predecessor, and all these rumors got boosted on Friday when an insider leaked key information about the handset, including details about the device’s speed, display quality and thickness.

Sonny Dickson, an Australian blogger known for his cutting-edge information from the technology industry, took to Twitter on Friday to leak some of the key specs of the iPhone 6. According to him, the next-generation iPhone could be 0.22 inches thick, compared to the 0.30 inches thickness of the existing iPhone 5s.

Dickson also spoke about the display quality of the iPhone 6. According to him, the new iPhone is likely to feature an Ultra Retina screen, which could boast a density of 389 pixels per inch. By comparison, the iPhone 5s’ display has 1136x640 pixel resolution at 326 ppi.

If the iPhone 6 comes with a 4.7-inch display as suggested by multiple media reports so far, obtaining the 389ppi density at that screen size would require the resolution to be higher than 720p (1280x720), but lower than 1080p (1920x1080), Phone Arena reported.

When it comes to the processor of the iPhone 6, Dickson said the handset cold be powered by a new A8 processor, which should be clocking at 2.6GHz. The iPhone 5s, on the other hand, features an A7 processor, clocking at 1.3 GHz.

Last week, Taiwan’s Commercial Times reported that an improved A8 processor for the iPhone 6 is already in production at Taiwan Semiconductor Manufacturing, or TSMC (NYSE:TSM). The report said that the new chip is based on TSMC’s 20-nanometer process technology, as opposed to the existing A7 chip, which was produced on Samsung’s (KRX:005935) 28-nanometer technology.

However, reports surfaced earlier this week saying that Samsung could split production of the A8 processor with TSMC, taking a larger share than previously suggested.

In addition to a larger display, the iPhone 6 is also rumored to sport a sapphire crystal display cover, and according to a report from DigiTimes Research on Friday, GT Advance Technologies (NASDAQ:GTAT), the company has partnered with Apple to open a sapphire plant in Mesa, Ariz., and is expected to supply 9 percent to 16.6 percent of the iPhone sapphire screen covers in 2014.

Here is an excerpt from the report:

Assuming that the new-generation iPhone will have a 5-inch screen, then the forecast sapphire revenues are translated into output of 6.27-11.6 million 5-inch sapphire-made screen covers. As Digitimes Research estimates that Apple will ship 70 million units of the new-generation iPhone in 2014, the output of sapphire screen covers from GTAT will account for 9.0-16.6% of the iPhone shipments.

Apple is widely rumored to incorporate a larger, scratch-resistant sapphire display as a key feature in the iPhone 6; the company currently uses the material for small iPhone elements like the camera lens and the home button of the iPhone 5s, MacRumors reported.

According to some analysts, an iPhone 6 with a bigger screen could also benefit Apple’s stock. While Brian Blair of Wedge Partners said that the company’s stock could rise between $600 and $650 over the next 12 months, Andy Hargreaves, an analyst at Pacific Crest, recently upgraded Apple's stock to “outperform,” and gave it a $635 price target.

Hargreaves even predicted that the iPhone 6 could be priced at $299 under a contract, $100 more than what Apple charges for the iPhone 5s. Based on current rumors and previous iPhone release schedules, the iPhone 6 is expected to be released in September.